So for about the past month or so, I've been racking my brain to try and figure out where the space on my C Drive has been disappearing to. I ran endless virus searches, malware searches, spyware searches, system cleanups, defragged over and over, CCleaned everything over and over - but none of these seemed to have any lasting effects. The spare volume on my C Drive jumped around a bit, but remained almost critically low.

I have Vista Home Premium installed on my C Drive partition, recovery files on another partition, and then Ubuntu on another partition. And that is pretty much it - except for a couple of mid-spec games running off the C Drive. I keep all my music and most of my software installed on external hard drives. So the volume problem was bizarre.

Then I noticed that every now and then, some DVD burning jobs were aborting midway through as there was "Not enough space on disc". I had presumed this was the actual DVD disc, but now I think it means there isn't enough space on the C drive to save a temporary file to for use during the burning process. After the last abort, WDM had left my C Drive with just 22kb of space on it.

I ran the burn again, using one of my external hard drives as the location for the temporary file; and sure enough it seems to have fixed the problem. But now I am left with this (potentially incomplete) img file - or whatever format WDM uses - that is no longer 'temporary' because the job couldn't be completed to remove the file.

Or at least that is my theory. Over the past month or so I've probably lost around 6gb of space on my C Drive and haven't made any drastic instals. But this seems an awful lot for just temporary failed DVD burn image files? Can anyone suggest:
(a) How to get rid of these incomplete temp files
(b) Perhaps there are other processes that are using up my hard drive space so rapidly that I am over looking. Can you suggest any other methods of tracking down the culprit?

Thanks so much. If you need further specs then ask.